It's likely they still have to deal with law suits, at least until the judge rules on the fine print.

It wouldn't surprise me if they have legal/expert support for certain cases. The last thing you want is some dumb client losing a case that creates precedent which ruins your business model.

They do more than sign, they manage the process and lifecycle of agreements.

You can buy a turnkey loan solution for example from them.

They help you manage the workflow of documents. As say a car dealership using docusign, you still provide the documents and actually have to use their tools to make the workflows unless you pay them to help. I don’t think they offer to actually write the contracts. You’d hire a local attorney or just digitize what you already have. That’s been my experience after a couple enterprise level deployments. I could be wrong and we just didn’t need it.